In many field, there exists a need for efficient, reliable mechanisms for rapidly and repetitively sampling aliquots of fluid while avoiding contamination or intermixing between successive samples. One such field in which the need is particularly acutely felt is that of clinical hematology instrumentation. In this field, dictates of economics and cost effectiveness encourage nearly continuous machine operation, with blood samples from different patients being analyzed in rapid succession. Preferably this operation is conducted by a relatively unskilled operator who needs only to deliver the sample to an entry point, actuate a starting switch, and thereafter remove first the sample, and subsequently, a data card carrying the results of the tests performed by the instrument. Clearly, the very nature and criticality of hematology require extreme isolation between successive tests, for any intermixing of successive samples would surely result in improper data and incorrect diagnoses. On the other hand, manpower, practicality and economics dictate that the intersample cleanup be as simple, automatic, and rapid as possible.
It is an object of the present invention to provide automated, self-cleaning sampling apparatus which will permit the use of a large variety of sample containers and sample container configurations.
It is a further object that all portions of the sampling mechanism which make contact with the sample be thoroughly and automatically washed between samples, with minimal risk of intersample contamination.
It is a still further object that the automatic cleaning sequence be performed substantially independently of the control of the operator, yet be clearly visible and understandable to even the most unskilled of operators, whereby a subsequent cycle is not initiated until the previous, sample, clean, and dry cycles are completed.
It is yet another object of the present invention to provide a sampling system wherein the sample delivery process and actuation of the sampling and cleaning operations might be accomplished by one and the same hand of the operator.
These and other objects are substantially accomplished in accordance with the principles of the present invention.